Justification:
This species is listed as Vulnerable as available information indicates that the species has undergone significant localized declines in the past and which are ongoing (e.g., in Puerto Rico, Netherlands Antilles, Florida, and Jamaica) due to bleaching and disease. The estimated decline of both destroyed and declining reefs is on the order of 38% over three generations (30 years). In localities affected by mass mortality events in the late 1980s, little or no recovery was observed; additionally, no information on recovery is available from the 2005 event. Since this species occurs in large overlapping shingles, and is susceptible to an extremely virulent disease (white plague) that readily spreads from one colony to another, this is likely to cause continued declines and may inhibit recovery.

Common in intermediate to deep water. This is the dominant species at the base of the reef in the southern and western Caribbean.

There is no species specific population information available for this species. However, there is evidence that overall coral reef habitat has declined, and this is used as a proxy for population decline for this species. This species is particularly susceptible to bleaching, disease, and other threats and therefore population decline is based on both the percentage of destroyed reefs and critical reefs that are likely to be destroyed within 20 years (Wilkinson 2004). We assume that most, if not all, mature individuals will be removed from a destroyed reef and that on average, the number of individuals on reefs are equal across its range and proportional to the percentage destroyed reefs. Reef losses throughout the species' range have been estimated over three generations, two in the past and one projected into the future.

The age of first maturity of most reef building corals is typically three to eight years (Wallace 1999) and therefore we assume that average age of mature individuals is greater than eight years. Furthermore, based on average sizes and growth rates, we assume that average generation length is 10 years, unless otherwise stated. Total longevity is not known, but likely to be more than ten years. Therefore any population decline rates for the Red List assessment are measured over at least 30 years. Follow the link below for further details on population decline and generation length estimates.

This species is found in fore reef, slope, deep channels and deep lagoon environments. Recorded from 10-76 m (Reed 1985), but most common from 15-25 m (E. Weil and A. Bruckner pers. comm.), and especially at shallower depths (10-15m) in highly turbid waters.

The major long-term threat to this species has been bleaching with reported mortality during the 1987/1988, 1990, 1995, 1998 and 2005 bleaching events in various places throughout the wider Caribbean, including Puerto Rico, Netherlands Antilles, Florida, and Jamaica (Sebens 1994, A. Bruckner, B. Precht and E. Weil pers. comm.). They are particularly susceptible to bleaching because they have very thin tissues and a limited ability to cope with the affects of temperature. Since 2001, there has been a dramatic increase in the occurrence of white plague and increasing rates of mortality. Localized declines result from other disease (black band) and high sedimentation.

In general, the major threat to corals is global climate change, in particular, temperature extremes leading to bleaching and increased susceptibility to disease, increased severity of ENSO events and storms, and ocean acidification.

Coral disease has emerged as a serious threat to coral reefs worldwide and a major cause of reef deterioration (Weil et al. 2006). The numbers of diseases and coral species affected, as well as the distribution of diseases have all increased dramatically within the last decade (Porter et al. 2001, Green and Bruckner 2000, Sutherland et al. 2004, Weil 2004). Coral disease epizootics have resulted in significant losses of coral cover and were implicated in the dramatic decline of acroporids in the Florida Keys (Aronson and Precht 2001, Porter et al. 2001, Patterson et al. 2002). Escalating anthropogenic stressors combined with the threats associated with global climate change of increases in coral disease, frequency and duration of coral bleaching and ocean acidification place coral reefs at high risk of collapse.

In the US, it is present in many MPAs, including Florida Keys National Marine Sanctuary, Biscayne N.P., Dry Tortugas National Park, Buck Island Reef National Monument and Flower Garden Banks National Marine Sanctuary. Also present in Hol Chan Marine Reserve (Belize), Exuma Cays Land and Sea Park (Bahamas). In US waters, it is illegal to harvest corals for commercial purposes.

There is a need for more quantitative information on the status of the populations and rates of recovery in deep-water habitats.

All corals are listed on CITES Appendix II. Parts of the species’ range fall within Marine Protected Areas.

Recommended measures for conserving this species include research in taxonomy, population, abundance and trends, ecology and habitat status, threats and resilience to threats, restoration action; identification, establishment and management of new protected areas; expansion of protected areas; recovery management; and disease, pathogen and parasite management. Artificial propagation and techniques such as cryo-preservation of gametes may become important for conserving coral biodiversity.